From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=192.198.163.9 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794516233; b=iS8RAv+u4qNES12i4W4DsH83N6SbIOK0KM0x0UyUrE9n8taDCrXthYTJvGnaFBQUj7EY mzKJsI8Faj1ehQ3V7P6nt2tkIRrrlIC5E6VAFuLcPtAjfvqf5zpUMEmpcyAexyxMLgxI8 yXjyxMiUeeGRYdZyElEoa/Og53rhbRRKsGJj7UFdJLUixO2njem75vkzPLMxjuSCpsV/+ wHLwObWDpz68w8QstifB/aP0tozyKUFzBsUOxzgzq5CCLIySntxEuWT37n+N97ZOx+gez I7kN22mlBd19aUZzx3NT3rcbSCYhqfUP2lsAe/DSDDkRxQkllJ45e178ch0ZufdW+Tg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794516233; h=DMARC-Filter:DKIM-Signature:X-CSE-ConnectionGUID:X-CSE-MsgGUID: X-IronPort-AV:X-IronPort-AV:Received:X-CSE-ConnectionGUID: X-CSE-MsgGUID:X-ExtLoop1:X-IronPort-AV:Received:From:To:Cc:Subject: Date:Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=BKyCixUwSDIl+QpToE4IrR4fhUODa76FLWdRkgjQn2o=; b=u4+5cCgPXPs78zqwtEu8VBK5fT1EFz1DYX4DWW3a2te9Bp1bm93R1qFPdpGiRUAinLJU XutNgx+1ZhrhV+jzocsEp6gyeYBSLA4cfRBAJoCmM7JfhOARBdFmZPprvtXcsgBcR1kbp ab2DseSHGQxUXRHDvNIJCwV7pLQBQlNnt8NBvi6ercCgW8fKlKEs+PmVqrCrh2sqDPmjk usV0BjqRdrXOgl3FHGrxWCUZ2QwL0XT6qYWgJAoWFKLdkY6gsBdZ8GF/7BpQPkMGbm+r7 r6MQ1Qrak+SMcGRI11uMPm7I+ru2jFhkmNAl28fvlm8i+V6ySDsoylA5eNJhtmvenyg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=DU+Fh+uz; arc=none smtp.remote-ip=192.198.163.9 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F21F66070F99; Thu, 12 Nov 2026 20:43:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org F21F66070F99 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=DU+Fh+uz DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1794516233; x=1826052233; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=SCOIvslnFKjewk4LTSgRHrl900PNWBuaD4bxZjViAN8=; b=DU+Fh+uzXMe47tAQa5B4Nmjbntk/Ui1EmWpzfhDAivUfnvNLXbxETNAx vn5hgNYm26JuS5HBQFmsvv4OOLK0pRoK0bjNpBesTcDiWe7dQlUQQCv5c cPxU6mhhGWl/k1QJDcG+Mr4ado0489IRXZcQ+HuD4noNym4ckUytrJOnP aBQTvDV418pb0mrJNG8Vmk/l4rBFcbN5QjhJxSHGF8FRVyo8kMTMMUYic r16A8P/RbSKdt25zz1rBKFcL2JmEbBmCAgqT/2bebGKfcCTcU4WH/OQZl B0ycnXNYtegGBWNUBZ9HOsXuXWukEHCDWseKr6x6GqzQtNnslhLJsNocg A==; X-CSE-ConnectionGUID: wad4MkYrToOPY9aL29vHqg== X-CSE-MsgGUID: LSUxr6qaTYeGvGQqkX5zHA== X-IronPort-AV: E=McAfee;i="6800,10657,11964"; a="3192332" X-IronPort-AV: E=Sophos;i="6.27,210,1787036400"; d="scan'208";a="3192332" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Nov 2026 12:43:52 -0800 X-CSE-ConnectionGUID: pdD0Bxj/T6CbNYemns7/3A== X-CSE-MsgGUID: hdzpDXtmTFyyQR9kZSJ5vw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,210,1787036400"; d="scan'208";a="9087948" Received: from 9cc2c43eec6b.jf.intel.com ([10.54.77.29]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Nov 2026 12:43:53 -0800 From: Zide Chen To: Sean Christopherson , Paolo Bonzini , Peter Zijlstra Cc: kvm@vger.kernel.org, Jim Mattson , Yosry Ahmed , Andi Kleen , Stephane Eranian , linux-kernel@vger.kernel.org, Mingwei Zhang , Zide Chen , Das Sandipan , Shukla Manali , Dapeng Mi , Xudong Hao Subject: [PATCH v4 20/21] KVM: x86/pmu: Advertise PerfMon version 5 on Intel hosts Date: Thu, 12 Nov 2026 13:32:26 -0700 Message-ID: <20261112203227.289379-21-zide.chen@intel.com> X-Mailer: git-send-email 2.56.1 In-Reply-To: <20261112203227.289379-1-zide.chen@intel.com> References: <20261112203227.289379-1-zide.chen@intel.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Dapeng Mi KVM currently caps the guest PerfMon version at 2 for all Intel platforms. Now that KVM emulates the basic architectural PMU features introduced in PerfMon versions 3 through 5, raise the guest PerfMon version to 5. Features that require additional emulation support, e.g. architectural LBR will be enabled separately. PerfMon versions 3 and 4 continue to be exposed as version 2 because KVM cannot safely virtualize AnyThread due to cross-VM information leakage. PerfMon v5 is supported because it provides the AnyThread-deprecated capability, allowing KVM to indicate that AnyThread is deprecated. When enable_mediated_pmu is disabled or in the non-Intel paths, KVM retains the existing cap of version 2. Signed-off-by: Dapeng Mi Signed-off-by: Zide Chen Reviewed-by: Jim Mattson --- v3: - Simplify version cap logic since mediated PMU already requires version >= 4. (Jim) v2: - Cap vPMU v3/v4 to v2, as AnyThread cannot be safely virtualized. (Sashiko) --- arch/x86/kvm/pmu.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 39fc3f72b92d..7b4137fbcb4f 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -175,7 +175,17 @@ void kvm_init_pmu_capability(struct kvm_pmu_ops *pmu_ops) } memcpy(&kvm_pmu_cap, &kvm_host_pmu, sizeof(kvm_host_pmu)); - kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2); + + /* + * PMU v3/v4 has AnyThread support, which KVM cannot safely virtualize. + * Only expose PMU v5+ for Intel mediated PMU, where AnyThread is + * deprecated; otherwise, cap at PMU v2. + */ + if (is_intel && enable_mediated_pmu && kvm_pmu_cap.version >= 5) + kvm_pmu_cap.version = 5; + else + kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2); + kvm_pmu_cap.cntr_mask64 &= GENMASK_ULL(pmu_ops->MAX_NR_GP_COUNTERS - 1, 0); kvm_pmu_cap.fixed_cntr_mask64 &= -- 2.56.1